This book inflamed witch hunts across Europe. Malleus Maleficarum (The Hammer of Witches) was a manual for witch hunters and judges to catch witches and stamp them out. It came out just prior to the protestant reformation and it was one of the most popular books amongst the reformers who were wanting to smash ‘evil’ out of their countries. Between 1487 and 1520, twenty editions of the Malleus were published, and another sixteen editions were published between 1574 to 1669. This book single-handedly launched centuries of witch hunts.

The Malleus Maleficarum, usually translated as the Hammer of Witches, is the best known treatise on witchcraft. It was written by the discredited Catholic clergyman Heinrich Kramer (under his Latinized name Henricus Institoris) and first published in the German city of Speyer in 1487. It endorses extermination of witches and for this purpose develops a detailed legal and theological theory. It has been described as the compendium of literature in demonology of the fifteenth century. The top theologians of the Inquisition at the Faculty of Cologne condemned the book as recommending unethical and illegal procedures, as well as being inconsistent with Catholic doctrines of demonology.

The Malleus elevates sorcery to the criminal status of heresy and recommends that secular courts prosecute it as such in order to extirpate witches. The recommended procedures include torture to effectively obtain confessions and the death penalty as the only sure remedy against the evils of witchcraft. At that time, it was typical to burn heretics alive at the stake and the Malleus encouraged the same treatment of witches. The book had a strong influence on culture for several centuries.

Jacob Sprenger’s name was added as an author beginning in 1519, thirty-three years after the book’s first publication and twenty-four years after Sprenger’s death; but the veracity of this late addition has been questioned by many historians for various reasons.

Kramer wrote the Malleus following his expulsion from Innsbruck by the local bishop, due to charges of illegal behavior against Kramer himself, and because of Kramer’s obsession with the sexual habits of one of the accused, Helena Scheuberin, which led the other tribunal members to suspend the trial.

It was later used by royal courts during the Renaissance, and contributed to the increasingly brutal prosecution of witchcraft during the 16th and 17th centuries.